Runaway gaps to the upside represent traders who did not get in during the initial move of the up trend and, while waiting for a retracement in price, decided it was not going to happen. Increased buying interest happens all of a sudden, and the price gaps above the previous day's close. This type of runaway gap represents a near-panic state in traders. There significant increase in volume during and after the runaway gap.
Why Tata Chemical qualifies as runaway gap.
1. Increased volumes post breakout
2. Breakout happened and it was not retested, showing momentum.
3. Post gap-up the momentum increased and we closed near day's high.
Based on the gap measure, (runaway gaps happen in middle of trend). Target based on that is 532 or 590.
Stoploss would be gap itself (ie close below 437).